Growing up in the New Jersey 'burbs, I imagined Mexico to be unrelieved desert. I think for all of us, the image of a man leaning up against a cactus, slumbering under his sombrero means only one thing: Mexico. Nobody tries to convey this idea using a palm tree as a backrest, much less a maple. The message is: Mexico means cactus, means desert.

But here in the Bajío, where we live, there is water, plenty of it. As much rain falls here as fell on my home in the Sonoma Valley, where fine wines are made. Enough for rivers to flow year-round. Enough to irrigate row crops such as broccoli. Enough to dry-farm corn.

Eyeballing the map of our marvelous botanical garden, El Charco del Ingenio, about 10% of the surface area is water.

Map: El Charco Del Ingenio AC

Most of the water is impounded in a reservoir, the Presa las Colonias. It's silted up now, which makes it an ideal refuge for waterfowl. Small islands have been built in the water for use as nesting sites.

The brown color of the water is caused by suspended fine clay particles. They are a sign of erosion, caused by deforestation and primitive farming methods. Little topsoil remains; mostly clay subsoil that washes into the waterways with each rain. The suspended particles would take years to precipitate out of the water.

Las Colonias Reservoir is formed by a dam constructed of stones and mortar by hand early in the 20th Century.

This rare view shows water cascading over the spillway, owing to recent rains.

Originally, water was carried in the long pipe running near the top of the canyon leading down from the dam. It was used to generate electricity at the Aurora fabric mill in town, an early application of hydroelectric energy in Mexico.

The factory no longer makes cloth. It has been recycled into a posh collection of galleries and boutiques. The great pipe that once carried the water down into town is broken.

The waters in this canyon had much earlier power-generating use, though. A mill, built at the end of the 16th Century, was used for grinding seeds and fulling wool cloth.

Actually, the name of the botanical gardens derives from this old mill. When I first tried to translate Charco del Ingenio, I was flummoxed by my Spanish-English dictionaries. The word meanings I found meant something like "mechanism puddle." Hmmm. That can't be right.

Charco del Ingenio probably means "mill pond." The Spanish words undoubtedly carry Mexican meanings, a situation that has tripped me up frequently. (Is there such a thing as a Mexican-English dictionary? I could sure use one.)

The old mill building still stands, but it has been converted to another use which I'll discuss in a future post.

The canyon below the dam is a lovely spot with sheer rock walls and year-round pools—a shady place to relax by quiet waters on a warm day. Here's how it appears during the dry season.

During the rainy season, small waterfalls cascade into and out of the pools.

The natural amphitheater formed by the canyon walls is occasionally used for concerts and other gatherings.

[Siesta image: Don and Carmen Sellers, Our Retirement to Sayula.]